Multiple ionization and fragmentation of isolated pyrene and coronene molecules in collision with ions

作者：Lawicki A^*; Holm A I S; Rousseau P; Capron M; Maisonny R; Maclot S; Seitz F; Johansson H A B; Rosen S; Schmidt H T; Zettergren H; Manil B; Adoui L; Cederquist H; Huber B A

来源：Physical Review A, 2011, 83(2): 022704.

DOI：10.1103/PhysRevA.83.022704

The interaction of multiply charged ions (He(2+), O(3+), and Xe(20+)) with gas-phase pericondensed polycyclic aromatic hydrocarbon (PAH) molecules of coronene (C(24)H(12)) and pyrene (C(16)H(10)) is studied for low-velocity collisions (v <= 0.6 a.u.). The mass spectrometric analysis shows that singly and up to quadruply charged intact molecules are important reaction products. The relative experimental yields are compared with the results of a simple classical over-the-barrier model. For higher molecular charge states, the experimental yields decrease much more strongly than the model predictions due to the instabilities of the multiply charged PAH molecules. Even-odd oscillations with the number of carbon atoms, n, in the intensity distributions of the C(n)H(x)(+) fragments indicate a linear chain structure of the fragments similar to those observed for ion-C(60) collisions. The latter oscillations are known to be due to dissociation energy differences between even-and odd-n C(n)-chain molecules. For PAH molecules, the average numbers of H atoms attached to the C(n)H(x) chains are larger for even-n reflecting acetylenic bond systems.

• 出版日期2011-2-8
• 单位中国地震局